Can I save a render region?
You can make a script like this:
import bpy

max_saves = 4  # if you have that many saved regions, trying to create a new one will throw an error
               # remove old saves to create a new one

save_name = &quot;restore_render_regions_{}.py&quot;

out = &quot;import bpy\n\n&quot;

for name, scene in bpy.data.scenes.items():
    out += f&quot;scene = bpy.data.scenes.get('{name}')\n&quot; \
    f&quot;if scene:\n&quot; \
    f&quot;    scene.render.border_min_x = {scene.render.border_min_x}\n&quot; \
    f&quot;    scene.render.border_max_x = {scene.render.border_max_x}\n&quot; \
    f&quot;    scene.render.border_min_y = {scene.render.border_min_y}\n&quot; \
    f&quot;    scene.render.border_max_y = {scene.render.border_max_y}\n&quot; \
    f&quot;# --\n\n&quot;
    
for i in range(max_saves):
    filename = save_name.format(i)
    if filename not in bpy.data.texts:
        break
else:
    raise MemoryError(&quot;Number of saved render region states exceeded the limit - increase the limit or &quot; \
        &quot;remove old saves&quot;)
        
file = bpy.data.texts.new(filename)
file.write(out)

Running it will create another script named restore_render_regions_{0}.py with saved region coordinates, so you can run the automatically generated script to restore the coordinates at any time (the Texts are saved with the file).